Lumbar disc replacement: preliminary results with ProDisc II after a minimum follow-up period of 1 year.

Total disc replacement has the potential to replace fusion as the gold standard surgical treatment of degenerative disc disease. Potential advantages of disc replacement over fusion include avoidance of pseudarthrosis, postoperative orthoses, and junctional degeneration. After observing satisfactory clinical results at 7-11 years' follow-up with the ProDisc first-generation implant, a second-generation prosthesis was designed. This study is a prospective analysis of the early results of total disc replacement with the ProDisc II total disc prosthesis. Fifty-three patients had single-level or multilevel disc replacement and were evaluated clinically and radiographically preoperatively and at mean 1.4-year follow-up. There were clinically and statistically significant improvements in back and leg pain Visual Analog Scale and Oswestry disability scores that were maintained at final follow-up. The clinical results of patients with single- and multilevel surgery were equivalent. Satisfactory results were achieved in 90% of patients who had previous lumbar surgery. Complications occurred in 9% of patients and included vertebral body fracture, transient radicular pain, implant malposition, and transient retrograde ejaculation. Three patients (6%) required reoperation to address complications. No mechanical failure of the implants or loosening was observed, and the prostheses retained motion. Randomized, prospective, long-term studies will be necessary to compare the effectiveness of arthrodesis with total disc replacement.